Flow cytometric analysis of mouse neurospheres based on the expression level of RANDAM-2

RANDAM-2, a type-I transmembrane antigen constitutively expressed on the neuronal cell lineage during mouse neurogenesis, shows the highest expression level between embryonic day 8.5 (E8.5) and E10.5. As the period well overlaps with the proliferating stages of neural stem cells (NSCs), it is conceivable that NSCs are efficiently separable based on the expression level of RANDAM-2. In this paper, we show that NSCs can be efficiently enriched as RANDAM-2(high+) cells by fluorescence-activated cell sorting. Many cells in the RANDAM-2(high+) cells had the characteristics of the self-renewal capability and potential for multilineage differentiation into neural cells. In contrast, almost all of the RANDAM-2(low+/-) cells exhibited not only the extremely low self-renewability but the differentiation capability restricted to neurons. These two subpopulations also differed from each other in terms of the expression level of molecules associated with neural differentiation. These findings demonstrate that RANDAM-2 can be regarded as a useful marker for enrichment of NSCs.